scholarly journals On Adhesive and Buckling Instabilities in the Mechanics of Carbon Nanotubes Bundles

2015 ◽  
Vol 82 (10) ◽  
Author(s):  
Xuance Zhou ◽  
Oliver M. O’Reilly
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Aligned Arrays ◽  
Individual Cnts ◽  
Synthesized Materials ◽  
New Criteria

Many recently synthesized materials feature aligned arrays or bundles of carbon nanotubes (CNTs) whose mechanical properties are partially determined by the van der Waals interactions between adjacent tubes. Of particular interest in this paper are instances where the resulting interaction between a pair of CNTs often produces a forklike structure. The mechanical properties of this structure are noticeably different from those for isolated individual CNTs. In particular, while one anticipates buckling phenomena in the forked structure, an adhesion instability may also be present. New criteria for buckling and adhesion instabilities in forklike structures are presented in this paper. The criteria are illuminated with a bifurcation analyses of the response of the forklike structure to applied compressive and shear loadings.

Effect of van der Waals Interactions on the Raman Modes in Single Walled Carbon Nanotubes

2001 ◽  
Vol 86 (17) ◽  
pp. 3895-3898 ◽  
Author(s):  
A. M. Rao ◽  
J. Chen ◽  
E. Richter ◽  
U. Schlecht ◽  
P. C. Eklund ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Van Der Waals ◽  
Single Walled Carbon Nanotubes ◽  
Van Der Waals Interactions ◽  
Single Walled Carbon ◽  
Raman Modes ◽  
Walled Carbon Nanotubes

ADHESION BETWEEN CARBON NANOTUBES AND SUBSTRATE: MIMICKING THE GECKO FOOT-HAIR

NANO ◽  
2007 ◽  
Vol 02 (03) ◽  
pp. 175-179 ◽  
Author(s):  
W. ZHOU ◽  
Y. HUANG ◽  
B. LIU ◽  
J. WU ◽  
K. C. HWANG ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Binding Energy ◽  
Continuum Model ◽  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Multi Wall Carbon Nanotubes ◽  
Pulling Force ◽  
Analytical Expressions

A continuum model is developed based on the van der Waals interactions to study the adhesion between multi-wall carbon nanotubes (MWCNT) and substrates. Simple, analytical expressions for the binding energy and pulling force are obtained in terms of the MWCNT radius, number of walls, and parameters in the van der Waals potential. For a 1 cm by 1 cm template with densely packed MWCNTs (50 nm in spacing), the total pulling force can reach 26.6 N and 21.9 N for the graphite and polyethylene substrates, respectively.

Effect of van der Waals Interaction Strength and Nanocluster Size on the Dynamical and Mechanical Properties of 1,4-cis-polybutadiene Melts

2012 ◽  
Vol 1424 ◽  
Author(s):  
Canan Atilgan ◽  
Ibrahim Inanc ◽  
Ali Rana Atilgan
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Bulk Modulus ◽  
Residence Time ◽  
Van Der Waals ◽  
Interaction Strength ◽  
Polymeric Materials ◽  
Van Der Waals Interactions ◽  
Increasing Trend ◽  
Dynamics Simulations

ABSTRACTUsing molecular dynamics simulations, we have investigated the effect of embedding nanoclusters of radius 3-7 Å on the dynamical and mechanical properties of 1,4-cispolybutadiene melts. To see the effect of polymer-nanocluster interaction strength on the bulk modulus, the van der Waals interactions (vdW) between the polymer chain and nanocluster have been varied from weak to very stong while keeping polymer-polymer and nanoclusternanocluster interactions constant. The modulus depends on the interaction strength, but not on nanocluster size. Residence time of chains on the surface of the nanocluster (τr) has an increasing trend that reaches to a plateau as the vdW strength is increased. τr also doubles from 100 ps to 200 ps as the nanocluster size is increased from 3 to 7 Å. Our findings give clues on how the properties of polymeric materials may be controlled by nanoparticles of different chemistry and size.

scholarly journals Fabrication and Properties of Macroscopic Carbon Nanotube Assemblies Transforming from Aligned Nanotubes

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Y. N. Zhang ◽  
G. Z. Sun ◽  
L. X. Zheng
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Radial Direction ◽  
Nanometer Scale ◽  
Intrinsic Properties ◽  
Aligned Carbon Nanotubes ◽  
Cnt Arrays ◽  
Individual Cnts ◽  
Time Ease

Macroscale assemblies of well-aligned carbon nanotubes (CNTs) can inherit intrinsic properties from individual CNTs and at the same time ease handling difficulties that occur at nanometer scale when dealing with individual CNTs. Herein, simple fabrication processes are introduced to produce a variety of macroscale CNT assemblies, including well-aligned CNT bundles, CNT films, and CNT fibers, from the same starting material: spinnable CNT arrays. The electrical and mechanical properties of the as-prepared CNT assemblies have been investigated and compared. It is found that CNT films show an electrical conductivity of 145~250 S cm−1which is comparable to CNT fibers, but two orders magnitude higher than that of conventional Bucky paper. CNT fibers exhibit diameter dependent tensile strength which is mainly attributed to the nonuniform twisting along the radial direction of fibers.

scholarly journals The influence of interlayer interactions on the mechanical properties of polymeric nanocomposites

2015 ◽  
Vol 80 (11) ◽  
pp. 1449-1459
Author(s):  
Mehrdad Jabbarzadeh ◽  
Amir Golkarian
Keyword(s):  
Mechanical Properties ◽  
Van Der Waals ◽  
Chemical Change ◽  
Van Der Waals Interactions ◽  
Multilayer Graphene ◽  
Polymeric Nanocomposites ◽  
Jones Potential ◽  
Nonlinear Spring ◽  
Linear Spring ◽  
Elastic Modules

In this paper the influence of types of interlayer interactions on the elastic modules of multilayer graphene sheets (GS) and nanocomposites is studied. The modeling and investigation of mechanical properties of graphite layers are performed using molecular mechanics (MM) method. Initially, due to improving the model and decreasing the amount of computations, three types of elements such as beam, linear spring and nonlinear spring are used. To continue, the mechanical properties of multilayers and nanocomposites are compared using three types of interlayer interactions. Initially, nonlinear spring defined by Leonard Jones potential is used to define interlayer interactions (ordinary case). To continue, linear spring with certain stiffness, to obtain an equal linear spring and also to investigate the ultimate capacity of interlayer interactions in the force translation, by increasing the stiffness of linear springs, is employed (chemical change). Then once by omitting all Van der Waals interactions and defects creation in graphite layers, they are devoted to create covalent interlayer interactions (using Morse potential) and another time, Van der Waals and covalent interlayer interactions are created spontaneously to study the properties of multilayers and nanocomposites (functionalization). The results are compared with other available literatures in this case to validate the modeling.

Mechanics of Ellipsoidal Carbon Onions Inside Multiwalled Carbon Nanotubes

2012 ◽  
Vol 3 (1) ◽  
Author(s):  
F. Sadeghi ◽  
R. Ansari
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Oscillation Frequency ◽  
Direct Method ◽  
Van Der Waals ◽  
Oscillatory Behavior ◽  
Van Der Waals Interactions ◽  
Continuum Approximation ◽  
Multiwalled Carbon ◽  
Carbon Onions

On the basis of the continuum approximation along with Lennard–Jones potential function, new semi-analytical expressions are presented to evaluate the van der Waals interactions between an ellipsoidal fullerene and a semi-infinite single-walled carbon nanotube. Using direct method, these expressions are also extended to model ellipsoidal carbon onions inside multiwalled carbon nanotubes. In addition, acceptance and suction energies which are two noticeable issues for medical applications such as drug delivery are determined. Neglecting the frictional effects and by imposing some simplifying assumptions on the van der Waals interaction force, a simple formula is given to evaluate the oscillation frequency of ellipsoidal carbon onions inside multiwalled carbon nanotubes. Also, the effects of the number of tube shells and ellipsoidal carbon onion shells on the oscillatory behavior are examined. It is shown that there exists an optimal value for the number of tube shells beyond which the oscillation frequency remains unchanged.

Sign in / Sign up

Export Citation Format

Share Document